The present invention relates to auxiliary devices for controlling winding doors or grilles, sectional doors or the like, of the type comprising a rotary control member adapted to be rotated manually in case of failure of the electric motor and reduction unit for example as a consequence of a short or break in the current supply system. This manual rotation of the rotary control member causes the axial movement of a sliding member coaxial to said control member against the force of resilient means through the medium of a cam device disposed in the interface between the control member and the sliding member. This sliding member supports a half-coupling adapted, beyond a predetermined sliding movement, to cooperate with a second matching half-coupling supported by the main shaft driving the motor and reduction unit connected kinematically to the winding door or grille, sectional door or the like. A device is provided for generating an antagonistic torque counteracting the rotation of the sliding member in order to cause the axial movement of this sliding member.